1. Field of the Invention
Embodiments of the present invention relate to internal combustion engines and, more particularly, to a fuel injection device for an internal combustion engine, and a method associated therewith.
2. Description of Related Art
In general, an internal combustion engine is an engine wherein combustion of fuel and an oxidizer (typically air) occurs in a confined space, such as a combustion chamber, to convert thermal energy into mechanical energy. Typically, these engines use a spark ignition method or compression ignition system to create combustion. The spark ignition method generally involves delivering fuel to the combustion chamber via a fuel injector wherein an air-fuel mixture is ignited by a spark from a spark plug, as known by those of ordinary skill in the art. In compression ignition systems, as typically used with diesel fuel and engines, the combustion is triggered by sufficiently high compression of fuel and air within the combustion chamber. However, incomplete combustion of carbonaceous fuel within such systems due to inherent inefficiencies may produce high pollution levels.
As such, Homogeneous Charge Compression Ignition (HCCI) combustion or low-temperature combustion modes are gaining traction, since such systems may provide ultra-low particulates and oxides of nitrogen emissions from internal combustion engines that may help to meet increasingly restrictive emission standards. However, precise and accurate control of the air-fuel mixing process in the engine cylinder, with improved injection strategies under wide operating speed and load regimes, is lacking in HCCI combustion technologies. Current fuel injection devices may not meet HCCI combustion requirements. HCCI combustion has the potential to reduce NOx and soot emissions from diesel engines and to reduce NOx, HC, and CO emissions from gasoline engines, while simultaneously increasing thermal efficiencies. However, HCCI technology faces critical design challenges to obtain homogenous air-fuel fixtures, to control ignition timing, and to expand to high load conditions. This may be particularly true for diesel engines, as the higher boiling point of diesel fuels makes mixture preparation even more challenging than the gasoline fuels.
Further, current fuel delivery techniques may lack flexibility in meeting the mixture requirements for HCCI due to fixed injection angles of the fuel by the fuel injection devices. Fuel-wall impingement and cylinder-liner wetting may occur for some current injection devices, which undesirably result in higher Hydrocarbon (HC) and carbon monoxide (CO) emissions and lower fuel efficiency. For example, in fuel injectors with large fixed injection angles, when the injection timing is very early in the compression stroke, severe wall wetting occurs with a significant amount of fuel impingement on the cylinder liner. However, for the conventional injection timing, liquid distribution is optimized in the piston bowl at large fixed injection angles. A narrow angle injector, on the other hand, provides very good fuel distribution for early injection timing, but not for conventional injection timing. As such, a single injection angle cannot adequately meet the air-fuel mixing requirements for injection strategies with very early or late injection timings.
Accordingly, there is needed an improved fuel injection device for providing improved operation of internal combustion engines employing direct injection technology.